In the various prior art processes wherein metals are produced from metal sub-halides, the resultant product metal is contaminated, at least to some extent, by by-product metal halide. Various means are proposed for separating the product metal and metal halide, including separate reduction and sponge growth reaction stages.
The process of the invention provides a method which yields good product metal/by-product metal halide separation, while providing a product metal sufficiently massed, agglomerated or consolidated so that it is readily handleable and processable.
U.S. Pat. Nos. 2,896,462; 2,950,963 and 3,069,255 describe methods of producing metals from metal sub-halides by multistage processes.
Other patents which describe related reduction processes include U.S. Pat. Nos. 2,963,632; 2,824,799; 2,910,357; 2,944,888 and 2,956,862.
The concept of a porous inert insulating layer between reacting components and the side walls of a reactor has been described in conjunction with the thermite process (Z. anorg. Chem. 64, 2n-24; C.A. 4, 874, [ 1910]). Insulation layers have also been used in the reduction of uranium and thorium (H. A. Whilhelm et al., Journal of Chem Ed., 37, 56, [1960]).